High pressure device



March 1-1, 1969 J. CRAWLEY ET AL 3,431,825

HIGH PRESSURE DEVICE Filed Oct. 11, 1966 Sheet of 2 FIG.|

March 11, 1969 J, CRAWLEY ET AL 3,431,825

HIGH PRESSURE DEVICE United States Patent Office 3,431,825 Patented Mar. 11, 1969 43,496/65 US. 01. 92-165 rm. (:1. F15b 15/14, 15/26 2 Claims ABSTRACT OF THE DISCLOSURE A high pressure device is disclosed having ram rod support means. Three types of supports are shown: hydraulically operable finger rams; relatively movable annular bushes; and plural support rods.

This invention relates to high pressure intensifiers of the kind embodying large and small rams working in tandem in communicating cylinders, the small ram being provided on or by an elongated relatively slender rod.

One use of such intensifiers is for purposes of, hydrostatic extrusion when the slender ram rod is subjected to considerable axial compression. A main object of this invention is to prevent failure of the ram rod due to buckling under such operating conditions.

Accordingly the invention provides a high pressure intensifier of the kind specified having support means arranged to provide relatively slidable radial support for said ram rod while permitting axial movement of the rams.

In order that the invention may be clearly understood and readily carried into effect embodiments thereof will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic axial sectional view showing one form of the invention embodied in a high pressure intensifier which is partly broken away,

FIGURE 2 is a view similar to FIGURE 1 but shows a second form of the invention,

FIGURE 3 is again a view similar to FIGURE 1 and shows a third form of the invention, and

FIGURE 4 is a cross-sectional view taken along the line AA of FIGURE 3.

Referring now to the drawings, in each embodiment the invention is applied to a high pressure intensifier for hydrostatic extrusion. The intensifier embodies large and small rams working in tandem in communicating low and high pressure chambers respectively designated 2 and 2a. The large ram working in the low pressure chamber 2, which can be pressurised through inlet 2b is conviently in the form of a piston 4 of relatively short axial length. The small ram working in the chamber 2a (see FIGURE 2) is in the form of a relatively long slender rod 5 which projects co-axially from the piston 4 constituting the large ram. This ram rod 5 extends axially through the centre of the low pressure chamber 2 to enter the high pressure chamber 2a which opens through one end of the low pressure chamber as shown. In the present examples this high pressure chamber 2a may also constitute an extrusion chamber.

In the first embodiment shown in FIGURE 1 of the drawings a high pressure intensifier of the invention has a plurality of hydraulic or pneumatic cylinders 1 spaced radially around the outside of the wall of the low pressure chamber 2, only one cylinder being shown in the crosssection of FIGURE 1. Each cylinder 1 is however of substantially identical form and has a finger ram 3 working therein and arranged to project in a fluid tight manner through a registering opening in the wall of the low pressure chamber 2. The cylinders exemplified by cylinder 1 may conveniently have their longitudinal axes in a common diarnetral plane. The finger ram 3 of each cylinder is of such a length that the outer end 7 thereof can be caused to exert radial pressure on the ram rod 5. For this purpose the outer ram end 7 may have an arcuate form.

The axial location of the radial cylinders 1 along the low pressure chamber 2 is preferably such that the support afforded to the ram rod 5 by each finger ram 3 will be in the region most subject to buckling. For operational purposes each ram 3 may be provided with differential pressure areas working in chambers 9 and 10 within its cylinder which chambers are connected by pipes 6 and 8 with the low pressure chamber 2 respectively at the rearmost pressurised end of the chamber and at a location intermediate the chamber ends.

The outermost chamber 9 in each cylinder 1 is arranged to be maintained at a constant pressure by way of pipe connection 6 to hold the associated finger ram 3 in an extended projecting position in which the finger ram end 7 bears on and supports the ram rod 5. When however the piston 4, during travel, uncovers the pipe connection 8 between the innermost chamber 10 in the cylinder and the rearmost pressurised portion of low pressure chamber 2, the innermost chamber 10 is pressurised for purpose of finger ram retraction.

To permit complete retraction of each finger ram 3 the hole through which it projects into the low pressure chamber 2 is countersunk as at 11 so that the outer ram end 7 can be retracted flush with the inner wall surface of the chamber 2. The larger ram can then freely pass the ram fingers 3 when the latter are in a retracted position.

In the second embodiment as shown in FIGURE 2 of the drawings, a high pressure intensifier of the invention has a plurality of supports preferably formed as annular bushes 1a, located co-axially along the ram rod 5. These supports or bushes 1a are each provided with an inner boss 12 which is a sliding fit on the rod 5 and with an outer rim 13 which bears slidably against the inner wall surface of the low pressure chamber 2.

On a working stroke of the rams 4 and 5 the supporting bushes 1a are then pushed from an intermediate support position by the piston 4, constituting the large ram, towards the end of the low pressure chamber 2 through which the high pressure chamber 2a opens. On a return stroke, the supporting bushes 1a are progressively spread along the ram rod behind the piston 4 by flexible interconnecting links 3a and thus returned to the intermediate support position.

In the third embodiment as shown in FIGURES 3 and 4 of the drawings a high pressure intensifier of the invention has radial supports for the ram rod 5 in the form of rod members 1b mounted parallel to the axis of the ram rod 5 at angularly spaced intervals therearound.

These rod members 1b may be of composite construction, as shown, each consisting of an inner rod and an outer bearing sleeve loosely carried on the inner rod. The inner rods are mounted in tension between the ends of the low pressure chamber 2 to provide greater resistance to bending and together with their associated sleeves extend slidably through sealed openings 3b in the piston 4 which constitutes the large ram. Alternatively the rod members may be one piece members mounted as aforesaid. The rams 4 and 5 are thus free to slide axially between and along the rod members 1b which afford radial support over the full length of the ram rod 5. The use of the sleeves improves the strength of the mounting area for the rod members, and these sleeves may conveniently be made of a bearing material.

We claim:

1. A high pressure device including a large ram slidable in a cylinder, a ram rod connected to said ram and extending outside said cylinder, a plurality of rod members each extending axially in tension between opposite ends of said cylinder, each of said rod members extending through sealed openings in the large ram and being arranged in radial contact with said ram rod to provide relatively slidable radial support for said ram rod while permitting axial movement of the ram.

2. A high pressure device as claimed in claim 1 wherein said rod members are each of composite construction comprising an inner rod carrying a loosely fitting outer bearing sleeve.

References Cited UNITED STATES PATENTS U.S. Cl. X.R. 

